Theory of dynamics of entangled rod-like polymers by use of a mean-field Green function formulation. II. Rotational diffusion

Rotational motion of entangled rod-like polymers in solutions is theoretically treated by using a mean-field Green function formulation for the rotational diffusion in an effective perturbation potential representing the hindrance effect by neighboring rods. A similar procedure to Part I of this series yields an explicit expression of the effective diffusion constant D _r as a function of the rod length and the polymer concentration for solutions in a wide range of concentrations from dilute to semidilute. In the high concentration limit, the present result is consistent with that obtained from the tube model of Doi-Edwards.